Systems
CVE-2026-97555
Heap overflow in Linux CIFS/SMB client DACL rewrite enabling kernel memory corruption.
Major vulnerability. Linux kernel vulnerability in CIFS/SMB client affects many distributions and can enable kernel compromise on systems mounting SMB shares.
- CVSS
- 8.8Highscored by the publisher (CNA)
- Exploited in the wild
- Not knownUnvetted proof-of-concept code on GitHub; not in CISA KEV
- EPSS
- 0.58%chance of exploitation in the next 30 daystop 52% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Fixed in < 5.12, >= 6.12.111 and <= 6.12.*, >= 6.18.53 and <= 6.18.*per the vendor; 2 more listed below
- Published
- 25 Sept 2026analysed here 28 Sept 2026
Do first. Upgrade to a fixed release: < 5.12, >= 6.12.111 and <= 6.12.*, >= 6.18.53 and <= 6.18.*, >= 7.2.7 and <= 7.2.* (and 1 more below).
Summary
Impact
Kernel heap overflow during SMB DACL rewrite; can cause kernel memory corruption leading to privilege escalation or remote kernel compromise when mounting malicious SMB shares.
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Linux | >= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < 7fa84c9ca690643f429ae2709584a47e74b572c9>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < 2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < 0ee150794c75bcd0be0e24ff3394f433cbae18cc5.12Vendor says fixed in: < 5.12, >= 6.12.111 and <= 6.12.*, >= 6.18.53 and <= 6.18.*, >= 7.2.7 and <= 7.2.*, >= 7.3-rc3 and <= * |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- Linux kernel (cifs/smb client)
- Hosts mounting CIFS/SMB shares
- Servers/desktops using cifs mounts
Fix and mitigation
Action required
Immediate action required
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Not listed as of our last sync.
- Public exploit code
- Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept
GitHub proofs of concept
- woshigenm/CVE-2026-975553 stars
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 25 Sept 2026Published
- 28 Sept 2026Analysed by vulneraibility.com3 days later
- 29 Oct 2026First proof-of-concept repository on GitHub (unvetted)31 days later
- 30 Oct 2026CVE record last updated2 days later
Common questions
Is CVE-2026-97555 being exploited?
Not confirmed. CVE-2026-97555 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.58% probability of exploitation in the next 30 days.
How severe is CVE-2026-97555?
CVE-2026-97555 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-97555?
Yes. A fix has been recorded for CVE-2026-97555. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-97555 affect?
CVE-2026-97555 affects Linux kernel (cifs/smb client), Hosts mounting CIFS/SMB shares, Servers/desktops using cifs mounts. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-97555?
Apply vendor/upstream kernel patches immediately; avoid untrusted SMB servers.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
7 references in the CVE record, grouped by the tags the record gives them.
Other links (7)
- git.kernel.org /stable/c/4e78b5ff13214353750b87283ff79f62510f5844
- git.kernel.org /stable/c/63c2fbde15ffc9a0c21adf670c38d028e20fa65c
- git.kernel.org /stable/c/d5cea6766ae1868a51c7d17d77d065b4f55c587f
- git.kernel.org /stable/c/fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1
- git.kernel.org /stable/c/7fa84c9ca690643f429ae2709584a47e74b572c9
- git.kernel.org /stable/c/2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd
Show 1 more
- git.kernel.org /stable/c/0ee150794c75bcd0be0e24ff3394f433cbae18cc
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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